Abstract:

Population genetic structure with 209 individuals in three located natural populations of Toona ciliata var. pubescens was analyzed with 8 microsatellite markers.This study intended to find out species evolutionary history and endangered mechanism and offer scientific foundation for establishing efficient conservation strategies. The spatial genetic structure of T.ciliata var. pubescens was measured with spatial autocorrelation analysis. Spatial autocorrelation coefficient, which was used to reveal spatial structure of genetic variation, was calculated within the populations of Yifeng, Binchuan and Shizong. The results showed: 1) The average number and the effective number of alleles(N_e) were 5.3 and 2.6, respectively; 2) The average observed heterozygosity was 0.599 0, while the average expected heterozygosity was 0.589 3; 3) There was significant variation in spatial genetic structure of natural population at Yifeng, indicated with significant positive autocorrelation over 0～240 m; 4) Genetic variance in populations of Binchuan and Shizong was distributed randomly; 5) Spatial genetic structure was mainly affected by limited dispersal of pollens and seeds, heterogeneity of microenvironment and density of population.

Key words: Toona ciliata var. pubescens, spatial genetic structure, spatial autocorrelation analysis, microsatellite